Field
The present disclosure relates to telecommunications apparatus and methods.
Description of Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
Third and fourth generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architectures, are able to support more sophisticated services than simple voice and messaging services offered by previous generations of mobile telecommunication systems.
For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy third and fourth generation networks is therefore strong and the coverage areas for these networks is expected to increase rapidly.
The anticipated widespread deployment of third and fourth generation networks has led to the parallel development of devices and applications which, rather than taking advantage of the high data rates available, instead take advantage of the robust radio interface and increasing ubiquity of the coverage area. Examples include so-called machine type communication (MTC) applications, which are typified by semi-autonomous or autonomous wireless communication devices (i.e. MTC devices) communicating small amounts of data on a relatively infrequent basis. Examples include so-called smart meters which, for example, might be located in a customer's house and periodically transmit information back to a central MTC server relating to the customer's consumption of a utility, such as gas, water, electricity and so on. Further information on characteristics of MTC-type devices can be found, for example, in the corresponding standards, such as ETSI TS 122 368 V10.530 (2011 July)/3GPP TS 22.368 version 10.5.0 Release 10) [1]. Some typical characteristics of MTC type terminal devices/MTC type data might include, for example, characteristics such as low mobility, high delay tolerance, small data transmissions, a level of predictability for traffic usage and timing (i.e. traffic profile), relatively infrequent transmissions and group-based features, policing and addressing.
Unlike a conventional third or fourth generation terminal device (such as a smartphone), an MTC-type terminal is preferably relatively simple and inexpensive and able to operate with relatively low power consumption. For example, it may often be the case that an MTC-type terminal is required to operate for an extended period of time without an external source of power. However, whilst it can be convenient for an MTC-type terminal to take advantage of the wide coverage area and robust communications interface provided by third or fourth generation mobile telecommunication networks, there are aspects of these networks which are not well suited to simple and inexpensive devices. This is because such networks are generally optimised for use by devices that require high data rates and low latency. Although power usage is an important consideration for such devices, it is to some extent of secondary concern to issues of data rates and latency. The type of functions performed by a typical MTC-type terminal on the other hand (for instance collecting and reporting back data on a relatively infrequent basis) do not typically require high data rates furthermore are typically not time-critical.
The inventors have recognised a desire to allow certain types of terminal device to operate within a mobile telecommunications network with lower power consumption than other conventional terminal devices operating within the network.